There is a strong parameters bypass vector in ActionPack.
Versions Affected: rails <= 6.0.3 Not affected: rails < 5.0.0 Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1
In some cases user supplied information can be inadvertently leaked from
Strong Parameters. Specifically the return value of each
, or each_value
,
or each_pair
will return the underlying "untrusted" hash of data that was
read from the parameters. Applications that use this return value may be
inadvertently use untrusted user input.
Impacted code will look something like this:
def update
# Attacker has included the parameter: `{ is_admin: true }`
User.update(clean_up_params)
end
def clean_up_params
params.each { |k, v| SomeModel.check(v) if k == :name }
end
Note the mistaken use of each
in the clean_up_params
method in the above
example.
Do not use the return values of each
, each_value
, or each_pair
in your
application.